/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.log4j.lf5.util;

import java.io.InputStream;
import java.net.URL;

/**
 * ResourceUtils. Provide a set of convenience methods for working with
 * Resources.
 * 
 * @see org.apache.log4j.lf5.util.Resource
 * 
 * @author Michael J. Sikorsky
 * @author Robert Shaw
 */

// Contributed by ThoughtWorks Inc.
public class ResourceUtils {
	//--------------------------------------------------------------------------
	// Constants:
	//--------------------------------------------------------------------------

	//--------------------------------------------------------------------------
	// Protected Variables:
	//--------------------------------------------------------------------------

	//--------------------------------------------------------------------------
	// Private Variables:
	//--------------------------------------------------------------------------

	//--------------------------------------------------------------------------
	// Constructors:
	//--------------------------------------------------------------------------

	//--------------------------------------------------------------------------
	// Public Methods:
	//--------------------------------------------------------------------------

	/**
	 * Get the InputStream for this resource. Note: to convert an InputStream
	 * into an InputReader, use: new InputStreamReader(InputStream).
	 * 
	 * @param object
	 *            The object to grab the Classloader from. This parameter is
	 *            quite important from a visibility of resources standpoint as
	 *            the hierarchy of Classloaders plays a role.
	 * 
	 * @param resource
	 *            The resource to load.
	 * 
	 * @return If the Resource was found, the InputStream, otherwise null.
	 * 
	 * @see Resource
	 * @see #getResourceAsURL(Object,Resource)
	 * @see InputStream
	 */
	public static InputStream getResourceAsStream(Object object,
			Resource resource) {
		ClassLoader loader = object.getClass().getClassLoader();

		InputStream in = null;

		if (loader != null) {
			in = loader.getResourceAsStream(resource.getName());
		} else {
			in = ClassLoader.getSystemResourceAsStream(resource.getName());
		}

		return in;
	}

	/**
	 * Get the URL for this resource.
	 * 
	 * @param object
	 *            The object to grab the Classloader from. This parameter is
	 *            quite important from a visibility of resources standpoint as
	 *            the hierarchy of Classloaders plays a role.
	 * 
	 * @param resource
	 *            The resource to load.
	 * 
	 * @return If the Resource was found, the URL, otherwise null.
	 * 
	 * @see Resource
	 * @see #getResourceAsStream(Object,Resource)
	 */
	public static URL getResourceAsURL(Object object, Resource resource) {
		ClassLoader loader = object.getClass().getClassLoader();

		URL url = null;

		if (loader != null) {
			url = loader.getResource(resource.getName());
		} else {
			url = ClassLoader.getSystemResource(resource.getName());
		}

		return (url);
	}

	//--------------------------------------------------------------------------
	// Protected Methods:
	//--------------------------------------------------------------------------

	//--------------------------------------------------------------------------
	// Private Methods:
	//--------------------------------------------------------------------------

	//--------------------------------------------------------------------------
	// Nested Top-Level Classes or Interfaces:
	//--------------------------------------------------------------------------

}
